Radio Inherited - Amerex AC301D - advice needed
First post and first attempt at "restoration" other than replacing belts and leaking capacitors. Be gentle 😉
By way of context - back in the day I used to visit my "uncle" (ie family friend) - I was obsessed with his 8 track stereo. This was circa 1978. I was 7. He died a couple of years ago and recently his wife died. When the family was going through his things, they found the Amerex and through family memory, someone remembered this weird kid who played with it nearly 4 years ago.
It arrived today and after some serious scrubbing (he was a 40 a day bloke all his life), I have ended up with an Amerex AC301D that has seen some better days. I dont want to junk it (memories and all that), but doubt it will be fully restorable without "donor" units.
So, I have:
- An AC301D that looks like the FM / Tuner board and tuner itself have been removed. (I have them but they are all hacked to pieces)
- The 8 track unit looks complete
- Cosmetically the unit is in good nick + original speakers.
You can see the missing FM board. In the picture below - the wires circled in RED lead directly to the 8-track unit. Those in Green appear to be the output from the amp leading to the speakers.
Image 2 - underside of the 8-track. Circled in RED are the wires from image 1. Circled in GREEN -- connected to the pre-amp / channel / tone board. Also can be seen the feed from the 8-track heads.
Image 3 - the transformer.
A labels the incoming supply. Output 1 is connected to the chassis - so I am assuming "ground". Output 2 (blue wire) to looks like it was connected to the removed FM board. 3 & 5 (RED) and 4 black.
Forgive the questions:
I'm really only interested in the 8-track, so will happily junk the FM / tuner circuitry.
- What I'm in the dark over are connections and voltages. The 8-track and FM unit look like they have neon bulbs, so would I be right in assuming this would be ~100V from the transformer?
- What would be the supply voltage to the 8-track unit itself?
- I can see no connection between the 8-track and the pre-amp / tone / balance unit (except what I am taking as power - red/black in image 2). From image 1, there are two leads (orange & yellow that lead into the 8-track -- should they in some way be connected to the pre-amp / tone / balance unit?
- Given the FM board has been removed (and is damaged) could I reassemble things so that just the 8-track works?
Is this worth salvaging - or should I junk the internals and use the case (which has cleaned up really well) to house something else?
Thanks in advance - and sorry for all the questions in a first post.
Welcome aboard, Glen.
Now, one of our members had one of these some eight years ago:
I don't know if he might be able to assist?
HI Cathovisor --> it was via that post that I came here. Will reach out.
It seems a shame not to try and ressurrect it in some way -- the FM/Tuner part is definitely dead. Looking for a way to "hot wire" the 8-track part really.
This unit looks familiar. I'm sure I have one, but it's a bit inaccessible at the moment.
Anyway, it shouldn't be too hard to get the 8 track player working on its own. It's basically a module with power in and audio out.
Looking at the small PCB underneath it, you can see two coaxial cables, black and grey. This is the audio input from the tape heads.
There's a red wire, this is power in (+12v DC typically) and a single black wire which is common ground (0v).
Left and right audio output is the yellow and orange wires. These go to the radio/tape/phono function switch on the front panel, then eventually to the onboard amplifier. You can connect the yellow and orange wires plus ground to an external amplifier, powered PC/iPod speaker or headphones to listen to the 8 track on its own.
Or you could try to make the onboard amplifier work. You can test it by selecting Phono on the function switch, then apply audio in (from eg. a CD/DVD player) to the phono sockets on the back. Sound should come out of the speakers. If the inbuilt amp doesn't work, you can either try to fault-find or use an external amplifier for the 8 track player, or fit a new amplifier module from China.
I think the 8 track player motor, track change solenoid and channel indicator lamps have another power supply. The lamps are low-voltage filament types, not neons. In any case, the power supply smoothing capacitor is rated 2200uF 25V so the voltage cannot be higher than that.
It looks like the grey wire from the mains transformer is soldered to the chassis. I suspect the blue wire supplies the 8 track motor, using the chassis as return to the grey wire. In that case it's an AC motor if the blue wire goes directly from the transformer to the motor. If there are diodes in the way, it's a DC motor. Some more pictures may help. Look for a label on the motor with the voltage details. Again 12v DC is typical for 8 track players. The manufacturers often used the same parts in car and home decks to achieve economies of scale.
I hope this has given you a few pointers. Good luck with it - I'm sure it's salvageable.